Earlier quoted context omitted.
about:config search for webfonts.enabled. change to false. alternatively, install noscript extension to have a UI with whitelist. if you are not using Firefox, then i have no sympaty. wait until google cares about you.
Also, in preferences, you can uncheck the box that allows sites to choose fonts. After I saw your comment I fired up Chrome to check and was surprised that there seems to be no option for this.
That means every site with a custom font from google now leaks the page and time you are accessing to them.
Same reason they forbid disabling 3rd party referrer on chrome.